RAM (Random Access Memory) modules are generally known in the art and common in use. They are employed for repeatedly storing and reading out data for a great number of applications. Special attention must be paid to the integrity of data stored in the RAM module when designing the memory architecture. In a prior art scheme, data integrity is ensured by a fully redundant design of the module in a relatively reliable fashion. A major shortcoming in this respect is, however, that the financial cost is relatively high.
In view of the above, an object of the present invention is to provide a method and a circuit configuration for storing data words in a RAM module whose demand in junction is considerably lower, without suffering from limitations with respect to data integrity.
This object is achieved by a method according to the following steps: producing a check bit word from at least one data word when writing the at least one data word into the RAM module, storing the check bit word, reading out the check bit word when reading out the at least one data word from the RAM module, regenerating the check bit word from the at least one read-out data word, comparing the read-out check bit word with the regenerated check bit word and generating an error message if they do not correspond.
Further, the object is achieved by a circuit configuration according to claim 7 which is characterized by: a first circuit unit for generating a check bit word from at least one data word when writing and reading the at least one data word, a number of registers for the associated storage of check bit words for the data words, and a second circuit unit by means of which, when reading data words, the associated check bit word is compared to the check bit word regenerated by the first circuit unit, and for generating an error message if the check bit words do not correspond.
A special advantage of this solution involves that in the event of basically equal data integrity as in the above-mentioned fully redundant design, the necessary silicon junction and, hence, the circuit design effort and costs is considerably lower.